A woman who left her mother on a soiled couch for years has been found guilty of failing to provide the necessaries of life to her mother.

Jo-Ann Quinn, 51, told the police she did the best she could to care for her difficult mother but Maureen Quinn wouldn't accept her help.

Judge Jonathan Down did not agree with Quinn's claims and found her guilty after a judge-only trial in the Napier District Court this week.

He said Maureen Quinn was severely dehydrated, malnourished and neglected when admitted to hospital on November 15 2011.

Judge Down said the warmth and comfort of touch must have been missing from Maureen Quinn's life. When Detective Toni Leppien touched her hand she said she said: "Your hand is so warm. I cannot remember the last time someone touched me."

Maureen Quinn had not moved from the couch for at least three years, the court was told.

Medical staff called to the house on November 15, 2011, found that the fibres of the blanket covering her had grown into a leg ulcer infested with maggots. Jo-Anne Quinn said it was the first time she had noticed the maggots.

Her mother's face was stained blue from the couch, and her left toenails were so long that they had become embedded in her right leg.

She died 36 days later of pneumonia.

She had existing heart trouble, type 2 diabetes and osteoporosis, and relied on her daughter's care.

Crown prosecutor Steve Manning argued that Quinn endangered her mother's life because she did not seek timely medical care.

The defence declined to give evidence.

Quinn said she was following her mother's wishes by not seeking medical help. "She doesn't like anything done, she does what she wants, " she said in a police interview played to the court.

She rang a doctor only after her sister in Australia raised concerns about how much pain their mother was in.

Judge Down said it was "too little too late".

Maureen Quinn was "skin and bones", dehydrated and malnourished when she arrived at Hawke's Bay Hospital, chief medical officer John Gommans said.

Medical staff gave her three litres of fluid in the first few hours of her arriving at the emergency department. It had not been done lightly, as too much fluid could cause heart failure. "The pain, fractures, medical conditions, maggots, wounds and impact it had on staff was stunning."

Maureen Quinn did not want to give a statement against her eldest daughter, telling police: "She looked after me the best she could."

"I can't believe I've had eight children and I've ended up here in this state, " she told Detective Toni Leppien.

Jo-Ann Quinn never visited her mother in hospital.

While awaiting this morning's decision a woman stormed into the courtroom and slapped Quinn in the face. The woman fled and has since been trespassed from the court.